Table iv

ABSTRACT

7. PROCESS FOR PREPARING A ALUMINUM ALLOY ROD FOR SUBSEQUENT USE IN THE PREPARATION OF AN ALUMINUM ALLOY WIRE HAVING A MINUMUM CONDUCTIVITY OF 61% IACS COMPRISING THE STEPS OF: A. ALLOYING FROM ABOUT 98.95 TO (ABOUT 99.54) LESS THAN 99.45 WEIGHT PERCENT ALUMINUM, FROM ABOUT 0.45 TO ABOUT 0.95 WEIGHT PERCENT IRON, ABOUT (0.01) 0.015 TO ABOUT 0.15 WEIGHT PERCENT SILICON, AND (FROM 0.0001 TO) TRACE QUANTITIES OF NO MORE THAN 0.05 WEIGHT PERCENT EACH OF TRACE ELEMENTS SELECTED FROM THE GROUP CONSISTING OF VANADIUM, COPPER, MAGNESIUM, MANGANESE, ZINC , BORON AND TITANIUM; THE TOTAL WEIGHT PERCENT OF TRACE ELEMENTS BEING (FROM 0.004 TO) NO MORE THAN 0.15 WEIGHT PERCENT; (AND THE RATIO OF IRON TO SILICON BEING AT LEAST 8:1;) B. CASTING THE ALLOY INTO A CONTINUOUS BAR IN A MOVING MOLD FORMED BY A GROOVE IN THE PERIPHERY OF A CASTING WHEEL AND AN ENDLESS BELT LYING ADJACENT THE GROOVE ALONG A PORTION OF THE PERIPHERY OF THE WHEEL; AND C. WITHOUT ANY PRELIMINARY OR INTERMEDIATE ANNEALS, (HOT) HOT-WORKING THE BAR SUBSTANTIALLY IMMEDIATELY AFTER CASTING WHILE THE BAR IS IN SUBSTANTIALLY THAT CONDITION AS CAST BY ROLLING THE BAR IN CLOSED ROLL PASSES TO OBTAIN A CONTINUOUS ALUMINUM ALLOY ROD (WITHOUT HAVING BEEN SUBJECTED TO ANY PRELIMINARY OR INTERMEDIATE ANNEALS) HAVING A CONDUCTIVITY OF LESS THAN 61% IACS. 13. PROCESS FOR PREPARING AN ALUMINUM ALLOY WIRE HAVING SUBSTANTIALLY EVENLY DISTRIBUTED IRON ALUMINATE INCLUSIONS OF A PARTICLE SIZE OF LESS THAN 2,000 ANGSTROM UNITS AND AN ELECTRICAL CONDUCTIVITY OF AT LEAST 61 PERCENT IACS COMPRISING THE STEPS OF: A. ALLOYING LESS THAN ABOUT 99.70 WEIGHT PERCENT ALUMINUM WITH MORE THAN ABOUT 0.30 WEIGHT PERCENT IRON, (NO MORE THAN) 0.015 TO ABOUT 0.15 WEIGHT PERCENT SILICON, AND TRACE QUANTITIES OF IMPURITIES; B. CONTINUOUSLY CASTING THE ALLOY INTO A CONTINUOUS BAR; C. CONTINUOUSLY ROLLING THE BAR IN SUBSTANTIALLY THAT CONDITION IN WHICH IT WAS CAST INTO A BAR TO FORM A CONTINUOUS ROD; D. DRAWING THE ROD WITH NO PRELIMINARY OR INTERMEDIATE ANNEALS TO FORM WIRE HAVE A CONDUCTIVITY OF LESS THAN 61% IACS; AND E. ANNEALING OR PARTIALLY ANNEALING THE WIRE.

United States Patent Re. 28,419 Reissued May 13, 1975 Int. Cl. B221125/00 US. Cl. 148-2 15 Claims Matter enclosed in heavy brackets Ifappears in the original patent but forms no part of this reissuespecification; matter printed in italics indicates the additions made byreissue.

ABSTRACT OF THE DISCLOSURE An aluminum alloy wire having an electricalconduc tivity of at least 61 percent based on the International AnnealedCopper Standard and unexpected properties of increased ultimateelongation, bendability and fatigue resistance when compared toconventional aluminum alloy wire of the same tensile strength. Thealuminum alloy wire contains substantially evenly distributed ironaluminate inclusions in a concentration produced by the addition of morethan about 030 Weight percent iron to an alloy mass containing less thanabout 99.70 weight percent aluminum, no more than 0.15 weight percentsilicon, and trace quantities of conventional impurities normally foundwithin a commercial aluminum alloy. The substantially evenly distributediron aluminate inclusions are obtained by continuously casting an alloyconsisting essentially of less than about 99.70 weight percent aluminum,more than 0.30 weight percent iron, no more than 0.15 weight percentsilicon and trace quantities of typical impurities to form a continuousaluminum alloy bar, hot-working the bar substantially immediately aftercasting in substantially that condition in which the bar is cast to formcontinuous rod which is subsequently drawn into wire withoutintermediate anneals and annealed after the final draw. After annealing,the wire has the aforementioned novel and unexpected properties ofincreased ultimate elongation, electrical conductivity of at least 61percent of the International Annealed Copper Standard, and increasedbendability and fatigue resistance.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a divisionof copending application Ser. No. 814,183, filed Apr. 7, 1969, now US.Pat. No. 3,512,221, which application is a continuation-in-part ofcopending application Ser. No. 779,376, filed Nov. 27, 1968, nowabandoned, which in turn, is a continuationin-part of copendingapplication Ser. No. 730,933, filed May 21, 1968, and now abandoned.

This invention relates to an aluminum alloy wire suitable for use as anelectrical conductor and mor particularly concerns an aluminum alloywire having an acceptable electrical conductivity and improvedelongation, bendability and tensile strength.

The use of various aluminum alloy wires (conventionally referred to asEC wire) as conductors of electricity is well established in the art.Such alloys characteristically have conductivities of at least 61percent of the International Annealed Copper Standard (hereinaftersometimes referred to as IACS) and chemical constituents consisting of asubstantial amount of pure aluminum and small amounts of conventionalimpurities such as silicon, vanadium, iron, copper, manganese,magnesium, zinc, boron and titanium. The physical properties of prioraluminum alloy wire have proven less than desirable in manyapplications. Generally desirable percent elongations have been obtainedonly at less than desirable tensile strengths and desirable tensilestrengths have been obtainable only at less than desirable percentelongations. In addition, the bendability and fatigue resistance ofprior aluminum alloy wires has been so low that the prior wire has beengenerally unsuitable for many otherwise desirable applications.

Thus, it becomes apparent that a need has arisen within the industry foran aluminum alloy electrically conductive wire which has both improvedpercent elongation and improved tensile strength, and also possesses anability to withstand numerous bends at one point and to resist fatiguingduring use of the conductor. Therefore, it is an object of the presentinvention to provide an aluminum alloy wire of acceptable conductivityand improved physical properties such that the conductor may be used innew applications. Another object of the present invention is to providean aluminum alloy wire having novel properties of increased ultimateelongation and tensile strength, improved bendability and fatigueresistance and acceptable electrical conductivity. These and otherobjects, features and advantages of the present invention will becomeapparent to those skilled in the art from a consideration of thefollowing detailed description of the invention.

In accordance with this invention, the present aluminum alloyelectrically conductive wire is prepared from an alloy comprising lessthan about 99.70 weight percent aluminum, more than about 0.30 weightpercent iron, and no more than 0.15 weight percent silicon. Preferably,the aluminum content of the present alloy comprises from about 98.95 toless than about 99.45 weight percent with particularly superior resultsbeing achieved when from about 99.15 to about 99.40 weight percentaluminum is employed. Preferably, the iron content of the present alloycomprises about 0.45 weight percent to about 0.95 weight percent withparticularly superior results being achieved when from about 0.50 weightpercent to about 0.80 weight percent iron is employed. Preferably, nomore than 0.07 weight percent silicon is employed in the present alloy.The ratio between the percentage iron and the percentage silicon must be1.99:1 or greater. Preferably, the ratio between percentage iron andpercentage silicon is 8:1 or greater. Thus, if the present aluminumalloy contains an amount of iron within the low area of the presentrange for iron content, the percentage of aluminum must be increasedrather than increasing the percentage of silicon outside the ratiolimitation previously specified. It has been found that properlyprocessed wire having aluminum alloy constituents which fall within theabove-specified ranges possesses acceptable electrical conductivity andimproved tensile strength and ultimate elongation and in addition has anovel unexpected property of surprisingly increased bendability andfatigue resistance.

The present aluminum alloy is prepared by initially melting and alloyingaluminum with the necessary amounts of iron or other constituents toprovide the requisite alloy for processing. Normally, the content ofsilicon is maintained as low as possible without adding additionalamounts to the melt. Typical impurities or trace elements are alsopresent within the melt, but only in trace quantities such as less than0.05 weight percent each with a total content of trace impuritiesgenerally not exceeding 0.15 weight percent. Of course, when adjustingthe amounts of trace elements due consideration must be given to theconductivity of the final alloy since some trace elements affectconductivity more severely than others. The typical trace elementsinclude vanadium, copper, manganese, magnesium, zinc, boron andtitanium. If the content of titanium is relatively high (but still quitelow compared to the aluminum, iron and silicon content), small amountsof boron may be added to tie-up the excess titanium and keep it fromreducing the conductivity of the wire.

Iron is the major constituent added to the melt to produce the alloy ofthe present invention. Normally, about [0.80] 0.50 weight percent isadded to the typical aluminum component used to prepare the presentalloy. Of course, the scope of the present invention includes theaddition of more or less iron together with the adjustment of thecontent of all alloying constituents.

After alloying, the melted aluminum composition is continuously castinto a continuous bar. The bar is then hot-worked in substantially thatcondition in which it is received from the casting machine. A typicalhot-working operation comprises rolling the bar in a rolling millsubstantially immediately after being cast into a bar.

One example of a continuous casting and rolling operation capable ofproducing continuous rod as specified in this application is as follows:

.A continuous casting machine serves as a means for solidifying themolten aluminum alloy metal to provide a cast bar that is conveyed insubstantially the condition in which it solidified from the continuouscasting machine to the rolling mill, which serves as a means forhot-forming the cast bar into rod or another hot-formed product in amanner which imparts substantial movement to the cast bar along aplurality of angularly disposed axes.

The continuous casting machine is of conventional casting wheel typehaving a casting wheel with a casting groove partially closed by anendless belt supported by the casting wheel and an idler pulley. Thecasting wheel and the endless belt cooperate to provide a mold into oneend of which molten metal is poured to solidify and from the other endof which the cast bar is emitted in substantially that condition inwhich it solidified.

The rolling mill is of conventional type having a plurality of rollstands arranged to hot-form the cast bar by a series of deformations.The continuous casting machine and the rolling mill are positionedrelative to each other so that the cast bar enters the rolling millsubstantially immediately after solidification and in substantially thatcondition in which it solidified. In this condition, the cast bar is ata hot-forming temperature Within the range of temperatures forhot-forming the cast bar at the initiation of hot-forming withoutheating between the casting machine and the rolling mill. In the eventthat it is desired to closely control the hot-forming temperature of thecast bar within the conventional range of hot-forming temperatures,means for adjusting the temperature of the cast bar may be placedbetween the continuous casting machine and the rolling mill withoutdeparting from the inventive concept disclosed herein.

The roll stands each include a plurality of rolls which engage the castbar. The rolls of each roll stand may be two or more in number andarranged diametrically opposite from one another or arranged at equallyspaced positions about the axis of movement of the cast bar through therolling mill. The rolls of each roll stand of the rolling mill arerotated at a predetermined speed by 6 directions. This varying surfaceengagement of the cast bar in the roll stands functions to knead orshape the metal in the cast bar in such a manner that it is worked ateach roll stand and also to simultaneously reduce and change thecross-sectional area of the cast bar into that of the rod.

As each roll stand engages the cast bar, it is desirable that the castbar be received with sufficient volume per unit of time at the rollstand for the cast bar to generally fill the space defined by the rollsof the roll stand so that the rolls will be effective to work the metalin the cast bar. However, it is also desirable that the space defined bythe rolls of each roll stand not be overfilled so that the cast bar willnot be forced into the gaps between the rolls. Thus, it is desirablethat the rod be fed toward each roll stand at a volume per unit of timewhich is sufficient to fill, but not overfill, the space defined by therolls of the roll stand.

As the cast bar is received from the continuous casting machine, itusually has one large flat surface corresponding to the surface of theendless band and inwardly tapered side surfaces corresponding to theshape of the groove in the casting wheel. As the cast bar is compressedby the rolls of the roll stands, the cast bar is deformed so that itgenerally takes the cross-sectional shape defined by the adjacentperipheries of the rolls of each roll stand.

Thus, it will be understood that with this apparatus, cast aluminumalloy rod of an infinite number of different lengths is prepared bysimultaneous casting of the molten aluminum alloy and hot-forming orrolling the cast aluminum bar.

The continuous rod produced by the casting and rolling operation is thenprocessed in a reduction operation designed to produce continuous wireof various gauges. The unannealed rod (i.e., as rolled to f temper) iscold-drawn through a series of progressively constricted dies, withoutintermediate anneals, to form a continuous wire of desired diameter. Atthe conclusion of this drawing operation, the alloy wire will have anexcessively high tensile strength and an unacceptably low ultimateelongation, plus a conductivity below that which is industry accepted asthe minimum for an electrical conductor, i.e., 61 percent of IACS. Thewire is then annealed or partially annealed to obtain a desired tensilestrength and cooled. At the conclusion of the annealing operation, it isfound that the annealed alloy wire has the properties of acceptableconductivity and improved tensile strength together with unexpectedlyimproved percent ultimate elongation and surprisingly increasedbendability and fatigue resistance as specified previously in thisapplication. The annealing operation may be continuous as in resistanceannealing, induction annealing, convection annealing by continuousfurnaces or radiation annealing by continuous furnaces, or, preferably,may be batch annealed in a batch furnace. When continuously annealing,temperatures of about 450 to about 1,200 F. may be employed withannealing times of about 5 minutes to about one ten-thousandths of aminute. Generally, however, continuous annealing temperatures and timesmay be adjusted to meet the requirements of the particular overallprocessing operation so long as the desired tensile strength isachieved. In a batch annealing operation, a temperature of approximately400 to about 750 F. is employed with residence times of about 30 minutesto about 24 hours. As mentioned with respect to continuous annealing, inbatch annealing the times and temperatures may be varied to suit theoverall process so long as the desired tensile strength is obtained.Simply by way of example, it has been found that the following tensilestrengths in the present aluminum wire;

are achieved with the listed batch annealing temperatures and times.

During the continuous casting of this alloy, a substantial portion ofthe iron present in the alloy precipitates out of solution as ironaluminate intermetallic compound (FeAl Thus, after casting, the barcontains a dispersion of FeAl in a supersaturated solid solution matrix.The supersaturated matrix may contain as much as 017 Weight percentiron. As the bar is rolled in a hot-working operation immediately aftercasting, the FeAl particles are broken up and dispersed throughout thematrix inhibiting large cell formation. When the rod is then drawn toits final guage size without intermediate anneals and then aged in afinal annealing operation, the tensile strength, elongation andbendability are increased due to the small cell size and the additionalpinning of dislocations by preferential precipitation of FeAl; on thedislocation sites. Therefore, new dislocation sources must be activatedunder the applied stress of the drawing operation and this causes boththe strength and the elongation to be further improved.

The properties of the present aluminum alloy wire are significantlyaffected by the size of the FeAl particles in the matrix. Coarseprecipitates reduce the percent elongation and bendability of the wireby enhancing nucleation and thus, formation of large cells which, inturn, lowers the recrystallization temperature of the wire. Fineprecipitates improve the percent elongation and bendability by reducingnucleation and increasing the recrystallization temperature. Grosslycoarse precipitates of FeAl, cause the wire to become brittle andgenerally unusable. Coarse precipitates have a particle size of below2,000 angstrom units.

A typical alloy No. 12 AWG wire of the present invention has physicalproperties of 15,000 p.s.i. tensile strength, ultimate elongation of 20percent, conductivity of 61 percent IACS, and bendability of 20 bends tobreak. Ranges of physical properties generally provided by No. 12 AWGwire prepared from the present alloy include tensile strengths of about12,000 to about 22,000 p.s.i., ultimate elongations of about 40 to about5 percent, conductivities of about 61 to about 63 percent and number ofbends to break of about 45 to 10.

A more complete understanding of the invention will be obtained from thefollowing examples.

EXAMPLE NO. 1

A comparison between prior EC aluminum alloy wire and the presentaluminum alloy wire is provided by preparing a prior EC alloy withaluminum content of 99.73 weight percent, iron content of 0.18 weightpercent, silicon content of 0.059 weight percent, and trace amounts oftypical impurities. The present alloy is prepared with aluminum contentof 99.45 weight percent, iron content of 0.45 weight percent, siliconcontent of 0.056 weight percent, and trace amounts of typicalimpurities. Both alloys are continuously cast into continuous bars andhot-rolled into continuous rod in similar fashion. The alloys are thencold-drawn through successively constricted dies to yield No. 12 AWGcontinuous wire. Sections of the wire are collected on separate bobbinsand batch furnace-annealed at various temperatures and for variouslengths of time to yield sections of the prior EC alloy and the presentalloy of varying tensile strengths. Several samples of each section aretested in a device designed to measure the number of bends required tobreak each sample at a particular flexure point. Through uniform forceand tension, the device fatigues each sample through an arc ofapproximately The wire is bent across a pair of spaced opposed mandrelshaving a diameter equal to that of the wire. The mandrels are spacedapart a distance of about 1 /2 times the diameter of the wire. One bendis recorded after the wire is deflected from a vertical disposition toone extreme of the arc, returned back to vertical, deflected to theopposite extreme of the arc, and returned back to the original verticaldisposition. The speed of deflection, force and tension aresubstantially equal for all tested samples. The results are as follows:

TABLE HA EC alloy Present alloy N0. of bends to break Average No. ofbends to break Tensile strength As shown in Table IIA, the present alloyhas a surprisingly improved property of bendability over conventional ECalloy.

Several samples of the present alloy No. 12 AWG wire and EC alloy No. 12AWG wire, processed as previously specified, are then tested for percentultimate elongation by standard testing procedures. At the instant ofbreakage, the increase in length of the wire is measured. The percentultimate elongation is then figured by dividing the initial length ofthe wire sample into the increase in length of the wire sample. Thetensile strength of the wire sample is recorded as the pounds per squareinch of cross-sectional diameter required to break the wire during thepercent ultimate elongation test. The results are as follows:

As shown in Table IIB, the present alloy has a surprisingly improvedproperty of percent ultimate elongation over conventional EC alloy.

EXAMPLES 2 THROUGH 7 Six aluminum alloys are prepared with varyingamounts of major constituents. Those alloys are reported in thefollowing table:

TABLE III Percent Example No. Al Fe Si remainder of the examples arebatch furnace annealed to yield the tensile strengths reported in TableIV. After annealing, each of the wires is tested for percentconductivity, tensile strength, percent ultimate elongation and averagenumber of bends to break by standard testing procedures for each, exceptthat the procedure specified in Example No. 1 is used for determiningaverage number of bends to break. These results are reported in thefollowing table.

TABLE IV Aver e Conductlv- Percent N ity in per- Tensile ultimate bandsto Example No. cent IACS strength elongation break From a review ofthese results, it may be seen that Example No. 2 falls outside the scopeof the present invention in percentage of components. In addition, itwill be noted for Example No. 2 that the percentage of ultimateelongation is somewhat lower than desirable and the average number ofbends to break the sample is lower than the remaining examples.

EXAMPLE NO. 8

An aluminum alloy is prepared with an aluminum content of 99.42 weightpercent, iron content of 0.50 weight percent, silicon content of 0.055weight percent and trace amounts of typical impurities. The alloy iscast into a continuous bar which is hot-rolled to yield a continuousrod. The rod is then cold-drawn through successively constricted dies toyield No. 12 AWG wire. The wire is collected on a 30 inch bobbin untilthe collected wire weighs approximately 250 pounds. The bobbin is thenplaced in a cold General Electric Bell Furnace and the temperaturetherein is raised to 480 F. The temperature of the furnace is held at480 F. for 3 hours after which the heat is terminated and the furnacecools to 400 F. The furnace is then quick cooled and the bobbin isremoved. Under testing, it is found that the alloy wire has aconductivity of 61.6 percent IACS, a tensile strength of 16,500 p.s.i.,a percentage of ultimate elongation of 20 percent, and a number of bendsto break of 18.

EXAMPLE NO. 9

Example 8 is repeated except the Bell Furnace temperature is raised to500 F. and held for 3 hours prior to cooling. The annealed alloy wirehas a conductivity of 61.4% IACS, a tensile strength of 15,000 p.s.i., apercentage of ultimate elongation of 27 percent, and a number of bendsto break of 28.

EXAMPLE NO. 10

Example No. 8 is repeated except the Bell Furnace temperature is raisedto 600 F. and held for three hours prior to cooling. The annealed alloywire has a conductivity of 61.2 percent IACS, a tensile strength of14,000 p.s.i., a percentage of elongation of 30 percent, and a number ofbends to break of 43.

EXAMPLE NO. 11

Example No. 8 is repeated except the Bell Furnace temperature is raisedto 600 F. and held 1 /5 hours prior to cooling. The annealed alloy has aconductivity of 61.5 percent IACS, a tensile strength of 16,000 p.s.i.,a percentage of elongation of 22 percent, and a number of bends to breakof 23.

EXAMPLE NO. 12

The alloy of Example No. 8 is cast into a continuous bar which ishot-rolled to yield a continuous f temper rod of inch diameter. The rodis then cold-drawn through successively constricted dies to yield No. 14AWG wire. The wire is then redrawn on a Synchro Model BG16 wire drawingmachine which includes a Synchro Resistioneal continuous in lineannealer. The wire is drawn to No. 28 AWG at a finishing speed of 3,300feet per minute and the in line annealer is operated at 52 volts with atransformer tap setting at No. 8. The annealed alloy wire has aconductivity of 62 percent IACS, a tensile strength of 15,450 p.s.i.,and a percentage of ultimate elongation of 25 percent. Since the wiregauge is so small, the number of bends to break is extremely large.

EXAMPLE NO. 13

The alloy of Example No. 8 is cast into a continuous bar which ishot-rolled to yield a continuous f temper rod of /8 inch diameter. Therod is then cold-drawn on a Synchro Style No. FX 13 wire drawing machinewhich includes a continuous in line annealer. The rod is drawn to No. 12AWG wire at a finishing speed of 2,000 feet per minute and the in lineannealer voltage at preheater No. 1 is 35 volts, at preheater No. 2 is35 volts, and at the annealer is 22 volts. The three transformer tapsare set at No. 5. The annealed alloy wire has a conductivity of 62percent IACS, a tensile strength of 16,300 p.s.i., and a percentage ofultimate elongation of 20 percent.

For the purpose of clarity, the following terminology used in thisapplication is explained as follows:

Rod--A solid product that is long in relation to its cross-section. Rodnormally has a cross-section of between 3 inches and 0.375 inch.

Wire-A solid wrought product that is long in relation to itscross-section, which is square or rectangular with sharp or roundedcorners or edges, or is round, a regular hexagon or a regular octagon,and whose diameter or greatest perpendicular distance between parallelfaces is between 0.374 inches and 0.003] inch.

While this invention has been described in detail with particularreference to preferred embodiments thereof, it will be understood thatvariations and modifications can be effected within the spirit and scopeof the invention as described hereinbefore and as defined in theappended claims.

I claim:

1. Process for preparing an aluminum alloy wire having an electricalconductivity of at least 61 percent IACS and iron aluminate inclusionswith a particle size of less than 2,000 angstrom units comprising thesteps of:

a. Alloying from about 98.95 to [about 99.54] less than 99.45 weightpercent aluminum, from about 0.45 to about 0.95 weight percent iron,about [0.01] 0.015 to about 0.15 weight percent silicon, and [less]trace quantities of no more than 0.05 weight percent each of traceelements selected from the group consisting of vanadium, copper,magnesium, manganese, zinc, boron and titanium; the total weight percentof trace elements being no more than 0.15 weight percent; [and the ratioof iron to silicon being at least 8: 1;]

b. Casting the alloy into a continuous bar in a moving mold formed by agroove in the periphery of a casting wheel and an endless belt lyingadjacent the groove along a portion of the periphery of the wheel;

c. Hot-working the bar substantially immediately after casting while thebar is in substantially that condition as cast by rolling the bar inclosed roll passes to obtain a continuous aluminum alloy rod;

. Drawing the rod with no preliminary or intermediate anneals to formwire having a conductivity of less than 61 percent IACS; and

e. Annealing or partially annealing the wire.

2. Process of claim 1 wherein step (a) comprises alloying from about98.95 to [about 99.44] less than about 99.45 weight percent aluminum,about [0.55] 0.54 to about 0.95 weight percent iron, from about [0.01]0.015

to about 0.15 weight percent silicon, and [less] trace quantities of nomore than 0.05 weight percent each of trace elements selected from thegroup consisting of vanadium, copper, magnesium, manganese, zinc, boronand titanium.

3. Process of claim 1 wherein the individual trace ele ment content isfrom 0.0001 to 0.05 weight percent and the total trace element contentis from 0.004 to 0.15 weight percent.

4. Process of claim 1 wherein step (e) comprises batch annealing orbatch partially annealing the wire.

5. Process for preparing an aluminum alloy wire having an electricalconductivity of at least 61 percent IACS comprising the steps of:

a. Alloying from about 98.95 to [about 99.54] less than 99.45 weightpercent aluminum with about 0.45 to about 0.95 weight percent iron,about [0.01] 0.015 to about 0.15 weight percent silicon, and [from0.0001 to] trace quantities of no more than 0.05 weight percent each oftrace elements selected from the group consisting of vanadium, copper,magnesium, manganese, zinc, boron and titanium, the total trace elementcontent being [from 0.004 to] no more than 0.15 weight percent.

b. Continuously casting the alloy into a continuous bar;

c. Continuously rolling the bar in substantially that condition in whichit was cast into a bar to form a continuous rod;

. Drawing the rod with no preliminary or intermediate anneals to formwire having a conductivity of less than 61 percent IACS; and [e.Annealing or partially annealing the wire] e. Annealing or partiallyannealing the wire.

6. Process of claim [20] 5 wherein step (a) comprises alloying fromabout 98.95 to less than [99.44] 99.45

weight percent aluminum, about [0.5 5] 0.54 to about 0.95 weight percentiron, from about [0.01] 0.015 to about 0.15 weight percent silicon, andfrom 0.0001 to 0.05 weight percent each of trace elements selected fromthe group consisting of vanadium, copper, magnesium, manganese, zinc,boron and titanium, the total trace element content being from 0.004 to0.15 weight percent.

7. Process for preparing an aluminum alloy rod for subsequent use in thepreparation of an aluminum alloy wire having a minimum conductivity of61% IACS comprising the steps of:

a. Alloying from about 98.95 to [about 99.54] less than 99.45 weightpercent aluminum, from about 0.45 to about 0.95 weight percent iron,about [0.01] 0.015 to about 0.15 weight percent silicon, and [from0.0001 to] trace quantities of no more than 0.05 weight percent each oftrace elements selected from the group consisting of vanadium, copper,magnesium, manganese, zinc, boron and titanium; the total weight percentof trace elements being [from 0.004 to] no more than 0.15 weightpercent; [and the ratio of iron to silicon being at least 8 1;]

. Casting the alloy into a continuous bar in a moving mold formed by agroove in the periphery of a casting wheel and an endless belt lyingadjacent the groove along a portion of the periphery of the wheel; and

c. Without any preliminary or intermediate anneals,

[Hot] hot-working the bar substantially immediately after casting whilethe bar is in substantially that condition as cast by rolling the bar inclosed roll passes to obtain a continuous aluminum alloy rod [withouthaving been subjected to any preliminary or intermediate anneals] havinga conductivity of less than 61% IACS.

8. Process of claim 7 wherein step (a) comprises alloying from about98.95 to [about 99.44] less than 99.45 weight percent aluminum, about[0.55] 0.54 to about 0.95 weight percent iron, from about [0.01] 0.015to about 0.15 weight percent silicon, and from 0.0001 to 0.05 weightpercent each of trace elements selected from the group consisting ofvanadium, copper, magnesium, manganese, zinc, boron and titanium, thetotal trace element content being from 0.004 to 0.15 weight percent.

9. Process for preparing an aluminum alloy wire having an electricalconductivity of at least 61 percent IACS and iron aluminate inclusionswith a particle size of less than 2,000 angstrom units comprising thesteps of:

a. Alloying from about 98.95 to [about 99.54] less than 99.45 weightpercent aluminum, from about 0.45 to about 0.95 weight percent iron,about [0.01] 0.015 to about 0.15 weight percent silicon, and [less]trace quantities of no more than 0.05 weight percent each of traceelements selected from the group consisting of vanadium, copper,magnesium, manganese, zinc, boron and titanium; the total weight percentof trace elements being no more than 0.15 weight percent: [and the ratioof iron to silicon being at least 8:l;]

. Casting the alloy to form a cast bar;

c. Hot-working the bar by rolling the bar in closed roll passes toobtain an aluminum alloy rod;

(1. Drawing the rod with no preliminary or intermediate anneals to formwire having a conductivity of less than 61% IACS; and

e. Annealing or partially annealing the wire.

10. Process for preparing an aluminum alloy wire having an electricalconductivity of at least 61 percent IACS comprising the steps of:

a. Alloying from about 98.95 to less than [99.44] 99.45 weight percentaluminum with about [0.55] 0.45 to about 0.95 weight percent iron, about[0.01] 0.015 to about 0.15 weight percent silicon, and [from 0.0001 to]trace quantities of no more than 0.05 weight percent each of traceelements selected from the group consisting of vanadium, copper,magnesium, manganese, zinc, boron and titanium. the total trace elementcontent being [from 0.004 to] no more than 0.l5 weight percent.

b. Casting the alloy into a cast bar;

c. Hot-rolling the bar to form a rod;

d. Drawing the rod with no preliminary or intermediate anneals to formwire having a conductivity of less than 61% IACS; and

e. Annealing or partially annealing the wire.

11. Process for preparing an aluminum alloy rod for subsequent use inthe preparation of an aluminum alloy wire having a minimum conductivityof 61% IACS comprising the steps of:

a. Alloying from about 98.95 to [about 99.54] less than 99.45 weightpercent aluminum, from about 0.45 to about 0.95 weight percent iron,about 0.015 to about 0.15 weight percent silicon, and [from about 0.0001to] trace quantities of no more than 0.05 weight percent each of traceelements selected from the group consisting of vanadium, copper,magnesium, manganese, zinc, boron and titanium; the total weight percentof trace elements being [from 0.004 to] no more than 0.15 weightpercent; [and the ratio of iron content of silicon content being atleast 8:1;]

. continuous casting the alloy to form a continuous cast bar; and[without any preliminary or intermediate anneals initiating hot workingthe cast bar to form an aluminum alloy rod before the cast bar hascooled to a temperature below its hot working temperature] c. withoutany preliminary or intermediate anneals,

initiating hot w rking the cast bar to form an aluminum alloy rod havinga conductivity of less than 61% IACS, said initiating beginning beforethe cast bar has cooled to a temperature below its hot workingtemperature.

12. Process for preparing an aluminum alloy wire having substantiallyevenly distributed iron aluminate inclusions of a particle size of lessthan 2,000 angstrom units and an electrical conductivity of at least 61percent IACS comprising the steps of:

a. Alloying less than about 99.70 weight percent aluminum with more thanabout 0.30 weight percent iron, [no more than] 0.015 to about 0.15weight percent silicon, and trace quantities of impurities;

b. Casting the alloy into a bar;

. [Rolling] Hot-rolling the bar to form rod;

. Drawing the rod with no preliminary or intermediate anneals to formwire having a conductivity of less than 61% IACS; and

e. Annealing or partially annealing the wire by batch annealing at atemperature of 400 F. to 750 F. for a time of 24 hours to 30 minutes orcontinuous annealing at a temperature of 450 F. to 1200 F. for a time ofminutes to one ten thousandth of a minute to obtain wire havingsubstantially evenly distributed iron aluminate inclusions of a particlesize of less than 2,000 angstrom units and a conductivity of at least61% IA CS.

13. Process for preparing an aluminum alloy wire having substantiallyevenly distributed iron aluminate inclusions of a particle size of lessthan 2,000 angstrom units and an electrical conductivity of at least 61percent IACS comprising the steps of:

a. Alloying less than about 99.70 weight percent aluminum with more thanabout 0.30 weight percent iron, [no more than] 0.015 to about 0.15weight percent silicon, and trace quantities of impurities;

b. Continuously casting the alloy into a continuous c. Continuouslyrolling the bar in substantially that condition in which it was castinto a bar to form a continuous rod;

d. Drawing the rod with no preliminary or intermediate anneals to formwire having a conductivity of less than 61% IACS; and

e. Annealing or partially annealing the wire.

14. Process for preparing an aluminum alloy wire having an electricalconductivity of at least 61% IACS comprising the steps of:

a. Alloying from about 0.30 to about 0.95 weight percent iron, about0.015 to about 0.15 weight percent silicon, and conventional impuritieswith from about 98.95 to less than 99.70 weight percent aluminum;

b. Casting the alloy into a bar;

c. Hot-rolling the bar to form rod before the bar has cooled to atemperature below its hot-rolling temperature;

d. Drawing the rod with no preliminary or intermediate anneals to formwire having a conductivity of less than 61% IACS; and

e. Annealing or partially annealing the wire by batch annealing at atemperature of 400 F. to 750 F. for a time of 24 hours to 30 minutes orcontinuous annealing at a temperature of 450 F. to 1200 F. for a time of5 minutes to one ten thousandth of a minute to obtain wire havingsubstantially evenly distributed iron aluminate inclusions of a particlesize of less than 2,000 angstrom units and a conductivity of at least61% IACS.

15. Process for preparing an aluminum alloy wire having an electricalconductivity of at least 61% IACS comprising the steps of:

a. Alloying from about 0.30 to about 0.95 weight percent iron, ab ut0.015 to about 0.15 weight percent silicon, and conventional impuritieswith from about 98.95 to less than 99.70 weight percent aluminum;

b. Continuously casting the alloy into a continuous bar;

c. Continuously rolling the bar in substantially that condition in whichit was cast into a bar to form a continuous rod;

Drawing the rod with no preliminary or intermediate anneals to form wirehaving a conductivity of less than 61% IACS; and

e. Annealing or partially annealing the wire to obtain wire havingsubstantially evenly distributed iron aluminate inclusions of a particlesize of less than 2,000 angstrom units and a conductivity of at least61% IACS.

References Cited The following references, cited by the Examiner, are ofrecord in the patented file of this patent or the original patent.

UNITED STATES PATENTS OTHER REFERENCES A. J. Field.: The ElectricalConductivity of Aluminum Wire, J. Inst. Metals, vol. 51, pp. 183-198(1933).

H. J. Miller: Heat-Treatment and Finishing Operations in the Productionof Copper and Aluminum Rod and Wire," J. Inst. Metals, vol. 83, pp.221-232 (1954-5).

G. Gauthier: The Conductivity of Super-Purity Aluminum: The Influence ofSmall Metallic Additions, 1. Inst. Metals, vol. 59, pp. 129-150 (1936).

Ya. M. Kurpotkin et al.: Effect of Small Impurities of Iron, Nickel andCobalt of the Mechanical Properties and Electrical Conductivity ofAluminum," Izv. Vysshikh Uchelon, Zavedenii, Energ. 8, No. 10, pp.112-116 (1965).

R. K. Vassel: Variation of Certain Properties of Aluminum ConductingWires With the Manufacturing Technology, Fmipari Kutat IntnzelKtizlemnyei, April 1960, pp. 221245.

A. Domony: Aluminum for Electrical Conductors," Light Metals, November1949, pp. 614-626.

R. Harrington: The Effects of Single Addition Metals on theRecrystallization, Electrical Conductivity and Rupture and RuptureStrength of Pure Aluminum, TASM, V01. 41, pp. 443-459 (1949).

Mawawo Kuroda: Scientific Papers of the Institute of Physical andChemical Research (Supplement) No. 14 (September 1931).

C. Panseri et al.: Allumino, vol. 29 (1960), pp. 231- 239.

Aluminum for Electrical Conductors," Light Metals (November 1949), pp.614-626.

P. Eversheim: Investigations of the Electrical Conductivity of Aluminum,Aluminum (July/August 1955), pp. 338-341.

CHARLES W. LANHAM, Primary Examiner D. C. REILEY III, Assistant ExaminerUS. Cl. X.R. 29S27.7, Dig. 11

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTIGN Patent No. RE. No.28,419 Dated May 13, 1975 Roger J. Schoerner Inventor(s) It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 5, lines 39 and 40 should read precipitates have a particle sizeof above 2,000 angstrom units and fine precipitates have a particle sizeof below 2,000 angstrom units.

Signccl and Scalcd this Fourth Day of October 1977 [SEAL] Arrest:

RUTH C. MASON LUTRELLE F. PARKER Attesling Ojficer Acting Commissionerof Patents and Trademarks Disclaimer Re 28,4l9.-R0ger J. Schoerner.Carrollton, Ga. METHOD OF FABRICAT- ING ALUMINUM ALLOY ROD. Patent datedMay 13, 1975. Disclaimer filed Mar. 17, 1983, by the assignee, SouthwireC0.

Hereby enters this disclaimer to claims l2, 13, 14 and 15 of saidpatent.

[Oflicial Gazette May 24. 1983.]

7. PROCESS FOR PREPARING A ALUMINUM ALLOY ROD FOR SUBSEQUENT USE IN THEPREPARATION OF AN ALUMINUM ALLOY WIRE HAVING A MINUMUM CONDUCTIVITY OF61% IACS COMPRISING THE STEPS OF: A. ALLOYING FROM ABOUT 98.95 TO (ABOUT99.54) LESS THAN 99.45 WEIGHT PERCENT ALUMINUM, FROM ABOUT 0.45 TO ABOUT0.95 WEIGHT PERCENT IRON, ABOUT (0.01) 0.015 TO ABOUT 0.15 WEIGHTPERCENT SILICON, AND (FROM 0.0001 TO) TRACE QUANTITIES OF NO MORE THAN0.05 WEIGHT PERCENT EACH OF TRACE ELEMENTS SELECTED FROM THE GROUPCONSISTING OF VANADIUM, COPPER, MAGNESIUM, MANGANESE, ZINC , BORON ANDTITANIUM; THE TOTAL WEIGHT PERCENT OF TRACE ELEMENTS BEING (FROM 0.004TO) NO MORE THAN 0.15 WEIGHT PERCENT; (AND THE RATIO OF IRON TO SILICONBEING AT LEAST 8:1;) B. CASTING THE ALLOY INTO A CONTINUOUS BAR IN AMOVING MOLD FORMED BY A GROOVE IN THE PERIPHERY OF A CASTING WHEEL ANDAN ENDLESS BELT LYING ADJACENT THE GROOVE ALONG A PORTION OF THEPERIPHERY OF THE WHEEL; AND C. WITHOUT ANY PRELIMINARY OR INTERMEDIATEANNEALS, (HOT) HOT-WORKING THE BAR SUBSTANTIALLY IMMEDIATELY AFTERCASTING WHILE THE BAR IS IN SUBSTANTIALLY THAT CONDITION AS CAST BYROLLING THE BAR IN CLOSED ROLL PASSES TO OBTAIN A CONTINUOUS ALUMINUMALLOY ROD (WITHOUT HAVING BEEN SUBJECTED TO ANY PRELIMINARY ORINTERMEDIATE ANNEALS) HAVING A CONDUCTIVITY OF LESS THAN 61% IACS. 13.PROCESS FOR PREPARING AN ALUMINUM ALLOY WIRE HAVING SUBSTANTIALLY EVENLYDISTRIBUTED IRON ALUMINATE INCLUSIONS OF A PARTICLE SIZE OF LESS THAN2,000 ANGSTROM UNITS AND AN ELECTRICAL CONDUCTIVITY OF AT LEAST 61PERCENT IACS COMPRISING THE STEPS OF: A. ALLOYING LESS THAN ABOUT 99.70WEIGHT PERCENT ALUMINUM WITH MORE THAN ABOUT 0.30 WEIGHT PERCENT IRON,(NO MORE THAN) 0.015 TO ABOUT 0.15 WEIGHT PERCENT SILICON, AND TRACEQUANTITIES OF IMPURITIES; B. CONTINUOUSLY CASTING THE ALLOY INTO ACONTINUOUS BAR; C. CONTINUOUSLY ROLLING THE BAR IN SUBSTANTIALLY THATCONDITION IN WHICH IT WAS CAST INTO A BAR TO FORM A CONTINUOUS ROD; D.DRAWING THE ROD WITH NO PRELIMINARY OR INTERMEDIATE ANNEALS TO FORM WIREHAVE A CONDUCTIVITY OF LESS THAN 61% IACS; AND E. ANNEALING OR PARTIALLYANNEALING THE WIRE.